1. Field of the Invention
The present invention relates generally to devices for protecting electronic components that are sensitive to electrostatic discharge (ESD). The present invention also relates to procedures for handling, shipping, storing and/or assembling such sensitive components. Examples of electrostatic discharge sensitive components include Si bipolar and MOSFET devices, and GaAs MESFET devices, and other devices.
2. Discussion of the Related Art
Electrostatic discharge sensitive components may require special handling while they are shipped, stored, assembled, etc. to avoid being damaged. Sometimes the components must be handled in class 1 or higher rooms to avoid degradation or damage due to electrostatic discharge. The required special handling may increase the cost of manufacturing the larger systems, such as circuit boards, that incorporate such components. In addition, the cost of replacing electronic components damaged by electrostatic discharge may increase the total cost of the manufacturing process.
Electrostatic discharge sensitive components are particularly susceptible to damage before they are electrically inserted into a larger system (such as a circuit board). Once the leads of the electronic component are electrically connected to the larger system, there is less risk of damage, since the gate/base, source/emitter and drain/collector leads are no longer the only paths for electrostatic discharge currents. Consequently, there is a need in the art for protective devices and procedures for protecting electrostatic discharge sensitive components prior to assembly of such components into circuit boards and the like.
It has been suggested to strap the terminals of component devices together by a series of thermocompression attached gold (Au) wire bonds, to dissipate electrostatic charges that could otherwise build up on the terminals. This thermocompression bonding process would be costly, however, both in terms of the required materials and the labor required to assemble and subsequently remove the wire bonds. In addition, it would be difficult to remove the bonds after the component devices are inserted into larger systems.
Others have suggested the use of packaging films with conductive slivers to protect sensitive electronic components. Such films are referred to in U.S. Pat. Nos. 5,314,732 and 5,165,985 (Wiste). The packaging films described in the Wiste patents would not be fully satisfactory, however, because they would not ensure electrical contact with the leads of the packaged component. Moreover, the packaging film would have to be at least partially removed from the component during assembly of the component into a circuit board. Consequently, the component would be susceptible to electrostatic discharge damage or degradation during the time while it is being assembled into the circuit board.
Other devices for providing electrostatic discharge protection are shown in U.S. Pat. No. 5,773,876 (Mekdhanasarn), U.S. Pat. No. 5,746,621 (Cronin), U.S. Pat. No. 5,652,410 (Hobbs), U.S. Pat. No. 5,163,850 (Cronin), and U.S. Pat. No. 5,108,299 (Cronin).
There is a need in the art for an uncomplicated, easy-to-use device or system for protecting electrostatic discharge sensitive components. There is also a need in the art for a convenient method of protecting such components while they are being assembled into circuit boards and the like.